Prepreg Fibre Content Measurement Using Laser Thickness Correlation

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Solution Overview

Problem

Existing methods for determining the fibre content in prepreg materials are destructive, uncertain, and require stopping production, lacking a continuous and non-destructive measurement solution.

Innovation Solution

A device and method that measures prepreg material thickness to indirectly determine fibre content using a database correlation, enabling continuous and non-destructive monitoring during production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If destructive methods (muffle combustion or acid dissolution) are used to separate fibre from matrix for weighing, then fibre content can be determined, but production must be stopped and the process is time-consuming

Engineering Contradiction:

Improvefibre content determinationVSAvoidproduction continuity

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces destructive chemical/thermal separation methods with a non-destructive optical measurement system. A laser module measures the thickness of the prepreg sheet continuously as it moves on the conveyor belt, eliminating the need to stop production for sample preparation and weighing. The fibre content is calculated from thickness measurements using a pre-established database, enabling continuous online monitoring without interrupting the manufacturing process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If discrete sampling and weighing is performed to determine fibre content, then measurement can be done, but the process is discontinuous and assumes homogeneity which may not be true

Engineering Contradiction:

Improvefibre content measurementVSAvoidmeasurement representativeness

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent implements continuous measurement of prepreg sheet thickness as the material moves continuously on the conveyor belt. The laser module takes multiple thickness measurements along the length and width of the sheet, providing ongoing data that represents the actual variation in fibre content throughout the entire sheet, rather than assuming homogeneity based on a single discrete sample.

Inventive Principle:

Principle #20Continuity of useful action

3Measurement precision

If traditional weighing methods are used to determine fibre content, then accurate measurement can be achieved, but the process is slow and cannot keep up with high-speed production

Engineering Contradiction:

Improvefibre content accuracyVSAvoidmeasurement speed

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The patent replaces slow mechanical weighing processes with rapid optical thickness measurement using a laser module. The laser can measure thickness instantaneously as the sheet passes by on the conveyor belt, providing real-time data at high speed. The fibre content is then calculated from these thickness measurements using a pre-established database, eliminating the time-consuming steps of sample collection, preparation, and weighing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If non-destructive thickness measurement is used to determine fibre content, then production continuity is maintained, but indirect measurement may reduce precision

Engineering Contradiction:

Improvecontinuous productionVSAvoidfibre content determination accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary work by creating a comprehensive database that establishes the relationship between prepreg sheet thickness and fibre content for different material combinations. This database is built beforehand using known fibre content values and corresponding thickness measurements. During continuous production, the system simply queries this pre-established database with the measured thickness values to obtain accurate fibre content calculations, eliminating the need for complex real-time analysis while maintaining precision.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables continuous, non-destructive measurement of fibre content in prepreg materials, ensuring high measurement speed and accuracy without interrupting the manufacturing process.

Implementation Method 1

a laser module (7) that measures a distance between said laser module (7) and said reflection plate (8)

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentEP4361556B1Device and method for measuring the fibre content of a sheet of prepreg material

Publication Date: 2025.10.08 IDEKO SCOOP

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AI summary

The invention relates to a device and method for measuring the fibre content of a sheet (4) of prepreg material, wherein the sheet (4) of prepreg material is formed by a fibre sheet (4.1) impregnated in a resin matrix. The method comprises: measuring the thickness of a sheet (4) of prepreg material; correlating the measurement of the thickness of the sheet (4) with a database comprising values of fibre content as a function of the thickness or range of thicknesses of the sheet (4) and as a function of the materials that make up the sheet (4), and; determining the fibre content of the sheet (4) of prepreg material as that value from the database corresponding to a sheet (4) made up of the same materials as the sheet (4) the thickness of which has been measured, and with a thickness or range of thicknesses comprising the measured thickness of the sheet (4).